Microsoft · Security update · February 10, 2026

KB5075899: February 2026 cumulative update for Windows Server 2025

KB5075899, released February 10, 2026, fixes 29 CVEs across 2 products. 5 of them are being exploited (CVE-2026-21510); 5 on CISA KEV. Patch Radar priority: Patch now.

Patch now5 on CISA KEV2 publicly disclosed
CVEs closed
29
None rated Critical
Exploited
5
CVE-2026-21510
Exploitation more likely
4
Vendor assessment
Highest EPSS
0.6124
99th percentile

Priority of the 29 CVEs

Patch now 5 Urgent 4 High 18 Routine 2

Applies to

ProductBuild after install
Windows Server 202526100.32370
Windows Server 2025 (Server Core installation)26100.32370

CVEs this fix closes

PriorityCVEComponentImpactCVSSEPSSExploitation
Patch now CVE-2026-21510 Windows Shell Security Feature Bypass 8.8 0.6124 KEVDisclosedExploited
Patch now CVE-2026-21513 MSHTML Framework Security Feature Bypass 8.8 0.1585 KEVDisclosedExploited
Patch now CVE-2026-21525 Windows Remote Access Connection Manager Denial of Service 6.2 0.0487 KEVExploited
Patch now CVE-2026-21533 Windows Remote Desktop Elevation of Privilege 7.8 0.0418 KEVExploited
Patch now CVE-2026-21519 Desktop Window Manager Elevation of Privilege 7.8 0.0248 KEVExploited
Urgent CVE-2026-21238 Windows Ancillary Function Driver for WinSock Elevation of Privilege 7.8 0.0338 More likely
Urgent CVE-2026-21241 Windows Ancillary Function Driver for WinSock Elevation of Privilege 7.0 0.0260 More likely
Urgent CVE-2026-21231 Windows Kernel Elevation of Privilege 7.8 0.0256 More likely
Urgent CVE-2026-21253 Mailslot File System Elevation of Privilege 7.0 0.0080 More likely
High CVE-2026-20846 Windows GDI+ Denial of Service 7.5 0.0143 Exploitation Less Likely
High CVE-2026-21243 Windows LDAP - Lightweight Directory Access Protocol Denial of Service 7.5 0.0143 Exploitation Unlikely
High CVE-2026-21244 Role: Windows Hyper-V Remote Code Execution 7.3 0.0133 Exploitation Less Likely
High CVE-2026-21248 Role: Windows Hyper-V Remote Code Execution 7.3 0.0133 Exploitation Less Likely
High CVE-2026-21250 Windows HTTP.sys Elevation of Privilege 7.8 0.0111 Exploitation Unlikely
High CVE-2026-21247 Role: Windows Hyper-V Remote Code Execution 7.3 0.0059 Exploitation Less Likely
High CVE-2026-21508 Windows Storage Elevation of Privilege 7.0 0.0045 Exploitation Less Likely
High CVE-2026-21246 Microsoft Graphics Component Elevation of Privilege 7.8 0.0045 Exploitation Unlikely
High CVE-2026-21232 Windows HTTP.sys Elevation of Privilege 7.8 0.0045 Exploitation Less Likely
High CVE-2026-21236 Windows Ancillary Function Driver for WinSock Elevation of Privilege 7.8 0.0045 Exploitation Unlikely
High CVE-2026-21239 Windows Kernel Elevation of Privilege 7.8 0.0045 Exploitation Less Likely
High CVE-2026-21245 Windows Kernel Elevation of Privilege 7.8 0.0045 Exploitation Less Likely
High CVE-2026-21251 Windows Cluster Client Failover Elevation of Privilege 7.8 0.0045 Exploitation Unlikely
High CVE-2026-21255 Role: Windows Hyper-V Security Feature Bypass 8.8 0.0038 Exploitation Less Likely
High CVE-2026-21242 Windows Subsystem for Linux Elevation of Privilege 7.0 0.0036 Exploitation Less Likely
High CVE-2026-21240 Windows HTTP.sys Elevation of Privilege 7.8 0.0028 Exploitation Less Likely
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